Image forming apparatuses such as laser printers, may utilize endless belts for conveyance mechanisms for conveying paper and intermediate transfer mechanisms for conveying developer images transferred from photosensitive drums. In such image forming apparatuses, belt cleaning devices using rollers and brushes are generally included to remove extraneous matters (residual toner, paper powder and the like) on the belts. For example, in Japanese Patent Laid-Open No. 2002-132060 and Japanese Patent Laid-Open No. 2003-345212, rotationally driven cleaning rollers which are brought into pressure contact with the surfaces of belts and to which bias voltage is applied, and electrostatically attracts extraneous matter on the belt while physically scraping them off, and scraping away the extraneous matters transferred to the cleaning rollers by blades.
In the image forming apparatuses which clean the belts by applying bias voltage to the above described cleaning rollers, the conductive members disposed around the cleaning rollers (for example, metal members supporting the above described blades) cause noise if they are electrically isolated, and therefore, they are generally connected to ground. In doing so, in order to avoid occurrence of current leak between the cleaning rollers and the conductive members, they have to be disposed to be separated at a certain distance, which exerts a harmful effect on reduction in size of the cleaning devices, and ultimately on the image forming apparatuses.